INFO: task syz-executor:14985 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:21928 pid:14985 tgid:14985 ppid:1      task_flags:0x400140 flags:0x00004004
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 schedule+0x165/0x360
 v9fs_evict_inode+0x170/0x320
 evict+0x504/0x9c0
 __dentry_kill+0x209/0x660
 dput+0x19f/0x2b0
 shrink_dcache_for_umount+0xa0/0x170
 generic_shutdown_super+0x67/0x2c0
 kill_anon_super+0x3b/0x70
 v9fs_kill_super+0x4c/0x90
 deactivate_locked_super+0xbc/0x130
 cleanup_mnt+0x425/0x4c0
 task_work_run+0x1d4/0x260
 exit_to_user_mode_loop+0xec/0x110
 do_syscall_64+0x2bd/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ffa5b98ff17
RSP: 002b:00007fff28a9afe8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007ffa5ba11c05 RCX: 00007ffa5b98ff17
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007fff28a9b0a0
RBP: 00007fff28a9b0a0 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007fff28a9c130
R13: 00007ffa5ba11c05 R14: 000000000004c620 R15: 00007fff28a9c170
 </TASK>
INFO: lockdep is turned off.
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 34 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250
 nmi_cpu_backtrace+0x39e/0x3d0
 nmi_trigger_cpumask_backtrace+0x17a/0x300
 watchdog+0xf93/0xfe0
 kthread+0x711/0x8a0
 ret_from_fork+0x3fc/0x770
 ret_from_fork_asm+0x1a/0x30
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31121 Comm: syz.1.5990 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x70
Code: 89 fb e8 23 00 00 00 48 8b 3d c4 49 fe 0b 48 89 de 5b e9 73 98 58 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <f3> 0f 1e fa 48 8b 04 24 65 48 8b 0c 25 08 50 a0 92 65 8b 15 e8 a4
RSP: 0018:ffffc9000b137608 EFLAGS: 00000046
RAX: 1ffff11026cc751d RBX: ffff88813663a8e8 RCX: 0000000000080000
RDX: ffffc90033411000 RSI: 000000000007ffff RDI: 0000000000080000
RBP: 0000000000000000 R08: ffff88801ca911b7 R09: 1ffff11003952236
R10: dffffc0000000000 R11: ffffed1003952237 R12: dffffc0000000000
R13: ffff88813663a8d0 R14: ffff88810cc88518 R15: ffff88813663a8e8
FS:  00007f7f6b9676c0(0000) GS:ffff8881a3c1b000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000006000 CR3: 00000000485d2000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 plist_del+0x62/0x3f0
 dequeue_pushable_task+0x2e/0x2d0
 dequeue_task_rt+0x25e/0x790
 __schedule+0x5f1/0x4cc0
 schedule+0x165/0x360
 schedule_timeout+0x12b/0x270
 snd_rawmidi_write+0x3a8/0xbd0
 vfs_writev+0x4b6/0x960
 do_writev+0x14d/0x2d0
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f7f6ab8ebe9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f7f6b967038 EFLAGS: 00000246 ORIG_RAX: 0000000000000014
RAX: ffffffffffffffda RBX: 00007f7f6adb5fa0 RCX: 00007f7f6ab8ebe9
RDX: 0000000000000002 RSI: 0000200000000840 RDI: 0000000000000009
RBP: 00007f7f6ac11e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f7f6adb6038 R14: 00007f7f6adb5fa0 R15: 00007ffce7642158
 </TASK>
